The field of the disclosure relates generally to equipment dry bays, and, more particularly, to mitigating effects of ignitions (e.g., explosions) that may occur in an equipment dry bay.
Fuel tanks and other systems typically include one or more equipment dry bays, such as the conventional equipment dry bay 10 shown in FIG. 1. Equipment dry bay 10 is defined by an outer wall 12 and an inner wall 14, and includes a plurality of pieces of electrical equipment 16. In the event that fuel leaks into equipment dry bay 10, faults in electrical equipment 16 may ignite the leaked fuel.
Accordingly, Federal Aviation Regulations require that areas where flammable fluids might leak include means to minimize the probability of ignition and means to minimize resultant hazards if ignition does occur. One of the hazards of an ignition occurring is that pressures within an unvented bay may increase substantially. For example, if ignition occurs in equipment dry bay 10, the pressure may increase from ambient to approximately 120 pounds per square inch absolute (psia). For normal operation, structural design pressures for equipment dry bay 10 may be much lower. Accordingly, to facilitate handling increased pressures generated by ignition, to increase strength, a typical equipment dry bay design would require additional structural material that is relatively expensive and relatively heavy.
In at least some known fuel tank assemblies, foam blocks are utilized to reduce ignition threats. The foam blocks have a cell structure that allows fuel to permeate the blocks, minimizing displacement of fuel. Further, the blocks suppress propagation of flames in the event ignition occurs. Such foam blocks may impede access to equipment and may themselves be flammable. In other known electrical enclosures, pressure generated from an ignition is vented to an external environment surrounding the enclosure. However, in some implementations, such as a fuel tank equipment bay in a pressurized cabin, it may not be feasible or desirable—or even compliant with regulations—to vent excess pressure to the surrounding environment.